Comminuted organic peroxide and process of obtaining same



cpose at low temperatures.

Patented Sept. 29, E925.

entree sates Estaterarest est tes;

THILO KROEBER, OF W'ESTEND, NEAR BERLIN, GERMANY, ASSIGNOR, BY MESNE AS- SIGNMENTS, TO N. V. INTERNATIONALE OXYGENIUM MAATSCHAPPIJ' NOVA- DEL, O'F DEVENTER, NETHERLANDS.

COMMINUTED ORGANIC P EROXIDE AND PROCESS OF OBTAINING SAME.

No Drawing.

To all whom it may concern:

Be it known that I, THILO KROEBER, a citizen of Germany, residing at Westend, near Berlin, Germany, have invented cer- 5 tain new and useful Improvements in Oomminuted Organic Peroxides and Processes of Obtaining Same, of which the following is a specification. The present invention refers to a proces for converting organic peroxides, especially benzoyl peroxide, into a finely divided state. The organic peroxides are among other purposes, used for bleaching solid or liquid sub stances, in which the peroxides are not soluble. For this purpose a very intimate mixture is required. Now the organic peroxides have the property that they can be comminuted with difficulty in the dry state because the organic peroxides tend to decom- If the organic peroxides are comminuted in disintegrat ing machines, as for example, in grinding mills, an increase in temperature is inevitable and decomposition of some of the 25 peroxide results, so that through the increased temperature, sintering takes place and the mass is partially decomposed.

Furthermore, :when it is attempted to grind, certain of the organic peroxides do verted into plate-like pieces.

The present process consists in comminuting the organic peroxides in the presence of water or other liquid having no act-ion upon organic peroxides, which liquid does not either decompose or dissolve any substantial amount of organic peroxides. The organic peroxides are mixed with the inactive liquid and the mixture is then subjected to a comminuting or grinding operation. By this procedure, a high state of division of the or ganic peroxides is obtained without decomposition. Hitherto the organic peroxides have been comminuted only in the dry state. The liquids used for the purpose herein are those in which the organic peroxides are.

practically insoluble,-or not dissolved in a considerable degree.

disassociationtakes place, and a division can be obtained to very small grains or particles, even considerably below one micron (1/1000 millimeter.) The comminuted or not crush into a fine powder, but are con- If one grinds a mixture of organic peroxldes with water, no evolution of oxygen or Application fled June 29, 1923. Serial No. 648,575.

ganic peroxides may then be easily and uniformly mixed with the materials to be bleached, whereby uniform bleaching to a desired extent may be easily obtained.

The process may be carried out for instance, by bringing into a cask or barrel as for instance, a Wooden barrel (which has no action on the organic peroxides), having acapacity of 24 liters, 3 kilograms of henzoyl peroxides or dibenzald' peroxide, !5

liters of water and 9 kilograms of balls of hard porcelain (of one size or of various sizes) or of any other hard material which will have no action on 'the'peroxides. One subjects the barrel to a rotating action for a period of from 4 to 16 hours, according to the mixture of the peroxides and the fineness of the product desired, the rotation being at the rate of from 40 to 60 revolutions per hour. 7

During this operation, the whole mass of organic peroxides is converted into a light thin paste. The organic peroxides may be easily separated from the liquid by filtra tion, for instance, by a suction filter or by gas pressure over orthrough the mixture. By prolonging the grinding, a paste can be obtained which may be stored, even after the addition of water, for several hours.

Suitable liquids for carrying out this proc ess are water, organic liquids unacted upon by organic peroxides, as for instance, benzol or cold alcohol. The grinding operation may be carried out at ordinary temperatures or below.

It will be seen that by this grinding proc: ess, I can reduce the particles to a grain size smaller than ordinary flour. In ordinary flour the size of the particlesvaries from about 20 to 60 microns.

I'do not herein claim the bleaching of specific substances, by the use of the finely powdered peroxides produced in accordance with the present invention, such subject matter bein claimed in a co-pending applicas oxide into a finely divided state which consists in mixing benzoyl peroxide with liquids inert thereto, andsubjecting the mixture to a solvent therefor and subjecting the mix-. ture to a grinding and rubbing operation for a period of from 4 to 16 hours. 4. The herein described new product comprising a mixture including an organic peroxide compound and a liquid which is inert compound bei thereto and which is a non-solvent thereof, a substantial portion of the said peroxide ticles of ordinary flour.

, 5. Anorganic peroxide the bulk of which is comminuted to a grain much finer than ordinary flour.

- 6.v Benzoyl peroxide in the form of particles, a part of which particles are not substantially' larger than one micron in size.

In testimony whereof I hereunto afiix my signature.

'rm'no KROEBER.-

.in the form of particles considerably smaller than the average par- 

